In structural engineering, the Eurocode serves as a trusted resource for connection design. However, as construction practices evolve, its limitations in handling complex connections, which constitute more than 80% of real-world scenarios, become evident.
To address this challenge, engineers turned to the Component-Based Finite Element Method (CBFEM), ushering in a revolution in connection design. IDEA StatiCa Connection implements CBFEM, and offers solutions for complex connections and simpler ones too.
The Eurocode’s limitations
The Eurocode is a comprehensive set of standards that provides guidelines for structural engineering, mainly in Europe. While it serves as a valuable resource for designing connections in many cases, it struggles when faced with complex connection designs.
The core issue lies in the Eurocode’s reliance on the component method, which simplifies connection design by breaking it down into individual components. This method, while suitable for straightforward connections, falls short when connections become more intricate and non-standard.
The prevalence of complex connection designs
In modern construction, architects and engineers are constantly pushing the boundaries of design, resulting in structures that demand innovative and adaptable connection solutions. As a result, complex connection designs are increasingly prevalent in real-world scenarios.
These complexities arise from various factors, such as unique architectural styles, retrofitting existing structures, accommodating unforeseen site conditions, or simply adhering to strict performance and safety requirements. In essence, 'complex' is the new norm in contemporary construction, emphasising the need for more versatile and robust design methodologies.
An outstanding illustration of a project that pushed the boundaries of connection design is the Curragh racecourse redevelopment undertaken by Kiernan Structural Steel Ltd.
This project featured a massive 7,200m² cantilevered roof for the grandstand, with spans ranging from 27m to 45m, establishing it as the largest cantilevered roof of its kind in Ireland (figure 1).
Figure 1: Complex connection construction example (Curragh racecourse project).
CBFEM: A solution for complex connections
Recognising the limitations of the component method in the face of complex connections, engineers sought a solution to bridge the gap. The Component-Based Finite Element Method (CBFEM) emerged as the answer. CBFEM extends the Eurocode’s capabilities by incorporating the Finite Element Method (FEM), as prescribed in Eurocode EN 1993-1-5.
This integration allows for a more detailed and accurate analysis of connections, making it suitable for complex designs. Moreover, it can be proved that the method is valid for other codes like AISC, for example.
Figure 2: Component method VS CBFEM method.
Revolutionising connection design
IDEA StatiCa Connection implements CBFEM to address the limitations of the component method, and ooffers a comprehensive suite of tools that empowers engineers to design connections efficiently, accurately, and with confidence, regardless of complexity.
By integrating the Finite Element Method, it provides a deeper understanding of the connection’s behaviour, allowing engineers to optimise designs and ensure safety while minimising material and construction costs.
In the case of Curragh racecourse – and due to the complex nature of the project – IDEA StatiCa was used for all of the 400 bespoke connections for the 1,100-tonne steel roof, and really proved beneficial when it was used to design two of the 'nodes' which support roughly a third of the entire roof area.
These 'nodes' had hundreds of load case combinations and weighed a massive 30 tonnes each. The use of IDEA StatiCa allowed for the most economical and efficient design of these two nodes to be possible.
Figure 3: Complex connections from design to construction (Curragh Racecourse project).
Conclusion
As construction practices advance, the need for versatile and robust design methodologies becomes clear. The Eurocode’s limitations in complex connection designs led to the development of CBFEM.
IDEA StatiCa Connection, with its CBFEM implementation, revolutionises connection design, offering efficiency, accuracy, and versatility. It’s not just a tool for complex connections but a comprehensive solution for all connection designs, setting new standards in the field.